(1) Field of the Invention
The present invention relates to a novel method for the treatment of endometriosis.
(2) Description of the Prior Art
Endometriosis appears as a product of atopic proliferation of endometrium. Internal endometriosis includes adenomyosis of uterus and endosalpingosis, and external endometriosis includes endometriosis of pelvic cavity and ectopic endometriosis. Endometriosis appears at a high incidence in females of 20-45 years old and its incidence has shown a steady increase in recent years, i.e., endometriosis is seen in 15-20% of females of 20-35 years old. Endometriosis is generally accompanied by dysmenorrhea and has a close relation to acyesis. Endometriosis is generally treated by pseudomenopausal treatment using danazol [Bonzal (trade name) manufactured by Tokyo Tanabe Seiyaku]. Buserelin [Suprecur (trade name) manufactured by Hoechst Japan] which is a LH-RH derivative has also been tried. However, danazol gives side effects such as dyshepatia, masculinization and the like and buserelin gives side effects such as hyposexuality, hot flushes and the like.
When medicinal treatments show no effect, a surgical treatment such as hysterectomy, lesion removal or the like is adopted but is not a desirable approach in view of the patient's response, the after effect, etc.
Therefore, development of an effective a drug is desired.
Meanwhile, the present inventors have for many years studied aromatase (a steroidogenesis enzyme) inhibitor.
It is known that 14.alpha.-hydroxy-4-androstene-3,6,17-trione and ester derivatives thereof have a strong aromatase-inhibitory activity. These compounds are disclosed in Japanese Patent Application Laid-Open Nos. 192794/1988, 131193/1989, etc. The present inventors studied the pharmacological activities of the compounds and found that the aromatase-inhibitory activity shown by the compounds is effective for treatment of endometriosis.